Method of ensuring consistent configuration between processors running different versions of software

Abstract

A method of establishing and maintaining a consistent configuration state of a first processor, running on a first version of operating software, and a second processor, running on a second version of operating software, is described. The method involves determining a current configuration state of the first processor, where the configuration state comprises a list of configuration commands. The method also involves performing a syntax check for each command in the current configuration, using the second processor and the second version of operating software, with the syntax check resulting in a pass or a fail result. For every command which results in a fail result, an entry is added to a mismatched configuration list (MCL). Embodiments of this invention can be utilized to keep the configurations consistent during an upgrade or downgrade of the operating software.

Description

BACKGROUND[0001]1. Field of the Invention[0002]Embodiments of the present invention relate to methods and systems for ensuring consistent configurations across multiple redundant processors in a stateful system.[0003]2. Related Art[0004]In order to provide greater reliability, many critical computing devices are equipped with multiple redundant processors. In such a system, processors can be classified as Active and Standby. The Active processor has control of the system. A Standby processor takes over if necessary, e.g., if the Active processor should fail. In order for such a switchover to be effected with minimal disruption of services, the Active and Standby processor(s) need to remain synchronized, particularly with respect to the configuration instructions being executed at a given time.[0005]In some situations, the Active and Standby processors can be running different versions of the same operating system. This can occur, for example, during a software upgrade (or downgrade)...

AI Technical Summary

Problems solved by technology

Routers with redundant processors are often used in environments where a lapse in connectivity caused by a failure in hardware or software would cause a loss of service.

This would lead to a configuration mismatch, as the Active and Standby processors would no longer be in sync with each other.

In such a case, the Standby processor would fail to take control of the router without interrupting service, if called upon to do so.

The Standby process could fail altogether when the switchover occurs.

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